Priti Chaudhari

Large classes are a reality in India and they pose particular challenges. People have varying opinions on how large the number of students should be in a so-called ‘large class ’. “There can be no quantitative definition of what constitutes a “large ” class, as perceptions of this will vary from context to context”. The two major educational challenges are that they make students feel anonymous and passive. Then, depending on how the teacher responds to these challenges, there may be second-level problems of class morale and discipline. In addition, the teacher faces inherent logistical problems, e.g., distributing and collecting homework, tests, handouts, posting grades, etc. To come over these problems, this research has been organized around a set of questions related to the two major educational challenges mentioned previously. In a language class in which student participation contributes greatly to the success of lectures, the number of students should be kept small so that in...

Cholesterol oxidase activity was studied during biotransformation of cholesterol to androsta-1,4-diene-3,17-dione (ADD) by Chryseobacterium gleum. Spent LB media, containing cholesterol (3 mM approximately = 1 g l(-1)) where the bacterium was grown for 24 h, at 30 degrees C with constant shaking at 120 rpm, had the highest enzyme activity (167 U mg(-1)). The growing cells produced 0.076 g ADD from 1 g cholesterol l(-1).

ABSTRACT Present study deals with the covalent modification of keratinolytic protease of Chryseobacterium gleum with higher enzyme activity, improved stability, non-immunogenicity and reusability. Protease of C. gleum showing feather degradation ability was modified by covalent attachment to polyethylene glycol. This modification culminated the change in electrophoretic mobility of protease in acrylamide gel. The modified enzyme showed 1.4 times more catalytic activity with better stability than native in aqueous system containing whole feathers as keratin. It showed improved pH, thermal, storage and solvent stability with a broadened range of pH (7–9) and temperature (25–50 °C) than native. The differentiation between modified and native enzyme was authenticated through UV–vis spectroscopy, SEM, XRD, FTIR and DSC. This modification of protease proved to be non-immunogenic in rats. The enzyme extracted after first run could be used for several cycles which clearly demonstrated its reusability in catalytic bioprocess of keratin degradation.

Chryseobacterium gleum exhibited complete dissolution of whole chicken-feathers (10gl− 1, pH 8) after 72h at 30° C through synthesis of keratinolytic protease when inoculated at 1%(v/v). This enzyme was purified to 67-fold with yield of 2.25% having a specific activity of 1670Umg− 1 and∼ 36kDa Mw. MALDI-TOF MS of this keratinase showed some similarity with the keratinase peptides of Bacillus subtilis (BOFXJ2). The keratinase action was inhibited by EDTA, iodoacetamide and metal ions like mercury, copper and zinc (1mM ...